Can this simple cannon work?
The trigger just stop the projectile being fired, and the O ring hold the air from leaking.
My idea came from spetsnaz ballistic knife, As I know ballistic knife is so powerful with spring, if it replaced with 150 PSI compressed air I think its gonna be so cool..

Here s the design

Edited by jrrdw, If you can't understand why, PM me only after reading the forum rules.

The idea certainly works, I had done some similar experimentation here.

You have a very short barrel though, so you need a heavy projectile and higher pressure to get better performance. A mountain bike shock pump will take you to 400 psi easily and cheaply. Why not stick a knife blade in it anyway

Similar to a idea sgort87 and a few of us was kicking around in the chat room a few moons ago. Your idea is smaller and more efficient. I like it. Why can't you call it a cannon? There are a lot of mini cannons here...

You know, a lot of homemade nerf guns use a clothespin and a rod for a trigger in a springer gun. This design is very similar to a springer and using a clothespin may be easier than custom building a trigger for it.